TRANSCRIPTIONAL REGULATION OF MAMMALIAN CYTOCHROME-C-OXIDASE GENES

The cytochrome c oxidase (COX) holoenzyme is a 13-subunit complex that carries out the terminal step in the electron transport chain. Three of the subunits, which contain the electron transfer function, are cod ed by mitochondrial DNA and the other ten subunits by nuclear DNA: Sin ce the holoenzyme contains equivalent amounts of each subunit, we and others have examined transcriptional regulation of COX nuclear subunit s to explore whether there is a common basis for co-regulation. Each g ene is seen to have a unique pattern of recognition by regulatory fact ors; although some factors bind to more than one gene, not all COX gen es seem to be regulated by the same set of factors. Current informatio n about the COX promoters that have been examined is summarized, and t he relation of promoter regulation to coordinate gene expression is di scussed.